linux/net/ipv6
Eric Dumazet e64e469b9a ipv6: addrconf: break critical section in addrconf_verify_rtnl()
Heiner reported a lockdep splat [1]

This is caused by attempting GFP_KERNEL allocation while RCU lock is
held and BH blocked.

We believe that addrconf_verify_rtnl() could run for a long period,
so instead of using GFP_ATOMIC here as Ido suggested, we should break
the critical section and restart it after the allocation.

[1]
[86220.125562] =============================
[86220.125586] WARNING: suspicious RCU usage
[86220.125612] 4.15.0-rc7-next-20180110+ #7 Not tainted
[86220.125641] -----------------------------
[86220.125666] kernel/sched/core.c:6026 Illegal context switch in RCU-bh read-side critical section!
[86220.125711]
               other info that might help us debug this:

[86220.125755]
               rcu_scheduler_active = 2, debug_locks = 1
[86220.125792] 4 locks held by kworker/0:2/1003:
[86220.125817]  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.125895]  #1:  ((addr_chk_work).work){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.125959]  #2:  (rtnl_mutex){+.+.}, at: [<00000000b06d9510>] rtnl_lock+0x12/0x20
[86220.126017]  #3:  (rcu_read_lock_bh){....}, at: [<00000000aef52299>] addrconf_verify_rtnl+0x1e/0x510 [ipv6]
[86220.126111]
               stack backtrace:
[86220.126142] CPU: 0 PID: 1003 Comm: kworker/0:2 Not tainted 4.15.0-rc7-next-20180110+ #7
[86220.126185] Hardware name: ZOTAC ZBOX-CI321NANO/ZBOX-CI321NANO, BIOS B246P105 06/01/2015
[86220.126250] Workqueue: ipv6_addrconf addrconf_verify_work [ipv6]
[86220.126288] Call Trace:
[86220.126312]  dump_stack+0x70/0x9e
[86220.126337]  lockdep_rcu_suspicious+0xce/0xf0
[86220.126365]  ___might_sleep+0x1d3/0x240
[86220.126390]  __might_sleep+0x45/0x80
[86220.126416]  kmem_cache_alloc_trace+0x53/0x250
[86220.126458]  ? ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.126498]  ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.126538]  ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.126580]  ? ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.126623]  addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.126664]  ? addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.126708]  addrconf_verify_work+0xe/0x20 [ipv6]
[86220.126738]  process_one_work+0x258/0x680
[86220.126765]  worker_thread+0x35/0x3f0
[86220.126790]  kthread+0x124/0x140
[86220.126813]  ? process_one_work+0x680/0x680
[86220.126839]  ? kthread_create_worker_on_cpu+0x40/0x40
[86220.126869]  ? umh_complete+0x40/0x40
[86220.126893]  ? call_usermodehelper_exec_async+0x12a/0x160
[86220.126926]  ret_from_fork+0x4b/0x60
[86220.126999] BUG: sleeping function called from invalid context at mm/slab.h:420
[86220.127041] in_atomic(): 1, irqs_disabled(): 0, pid: 1003, name: kworker/0:2
[86220.127082] 4 locks held by kworker/0:2/1003:
[86220.127107]  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.127179]  #1:  ((addr_chk_work).work){+.+.}, at: [<00000000da8e9b73>] process_one_work+0x1de/0x680
[86220.127242]  #2:  (rtnl_mutex){+.+.}, at: [<00000000b06d9510>] rtnl_lock+0x12/0x20
[86220.127300]  #3:  (rcu_read_lock_bh){....}, at: [<00000000aef52299>] addrconf_verify_rtnl+0x1e/0x510 [ipv6]
[86220.127414] CPU: 0 PID: 1003 Comm: kworker/0:2 Not tainted 4.15.0-rc7-next-20180110+ #7
[86220.127463] Hardware name: ZOTAC ZBOX-CI321NANO/ZBOX-CI321NANO, BIOS B246P105 06/01/2015
[86220.127528] Workqueue: ipv6_addrconf addrconf_verify_work [ipv6]
[86220.127568] Call Trace:
[86220.127591]  dump_stack+0x70/0x9e
[86220.127616]  ___might_sleep+0x14d/0x240
[86220.127644]  __might_sleep+0x45/0x80
[86220.127672]  kmem_cache_alloc_trace+0x53/0x250
[86220.127717]  ? ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.127762]  ipv6_add_addr+0xfe/0x6e0 [ipv6]
[86220.127807]  ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.127854]  ? ipv6_create_tempaddr+0x24d/0x430 [ipv6]
[86220.127903]  addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.127950]  ? addrconf_verify_rtnl+0x339/0x510 [ipv6]
[86220.127998]  addrconf_verify_work+0xe/0x20 [ipv6]
[86220.128032]  process_one_work+0x258/0x680
[86220.128063]  worker_thread+0x35/0x3f0
[86220.128091]  kthread+0x124/0x140
[86220.128117]  ? process_one_work+0x680/0x680
[86220.128146]  ? kthread_create_worker_on_cpu+0x40/0x40
[86220.128180]  ? umh_complete+0x40/0x40
[86220.128207]  ? call_usermodehelper_exec_async+0x12a/0x160
[86220.128243]  ret_from_fork+0x4b/0x60

Fixes: f3d9832e56 ("ipv6: addrconf: cleanup locking in ipv6_add_addr")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29 14:23:38 -05:00
..
ila rhashtable: Change rhashtable_walk_start to return void 2017-12-11 09:58:38 -05:00
netfilter netfilter: remove messages print and boot/module load time 2018-01-19 18:39:49 +01:00
addrconf_core.c net: ipv6: Make inet6addr_validator a blocking notifier 2017-10-20 13:15:07 +01:00
addrconf.c ipv6: addrconf: break critical section in addrconf_verify_rtnl() 2018-01-29 14:23:38 -05:00
addrlabel.c rtnetlink: ipv6: convert remaining users to rtnl_register_module 2017-12-04 13:35:36 -05:00
af_inet6.c ipv6: Fix SO_REUSEPORT UDP socket with implicit sk_ipv6only 2018-01-29 11:37:40 -05:00
ah6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
anycast.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
calipso.c net, calipso: convert calipso_doi.refcount from atomic_t to refcount_t 2017-07-04 22:35:16 +01:00
datagram.c net: ipv6: Allow connect to linklocal address from socket bound to vrf 2018-01-08 14:11:18 -05:00
esp6_offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-23 13:51:56 -05:00
esp6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-17 00:10:42 -05:00
exthdrs_core.c net: ipv6: remove unused code in ipv6_find_hdr() 2017-10-05 21:53:02 -07:00
exthdrs_offload.c ipv6: fix exthdrs offload registration in out_rt path 2015-09-02 15:31:00 -07:00
exthdrs.c ipv6: sr: fix TLVs not being copied using setsockopt 2018-01-10 16:03:55 -05:00
fib6_notifier.c net: Add module reference to FIB notifiers 2017-09-01 20:33:42 -07:00
fib6_rules.c net: ipv6: avoid overhead when no custom FIB rules are installed 2017-08-08 21:40:08 -07:00
fou6.c fou: make local function static 2017-05-21 13:42:36 -04:00
icmp.c ipv6: mark expected switch fall-throughs 2017-10-18 14:13:08 +01:00
inet6_connection_sock.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-28 10:33:06 -05:00
inet6_hashtables.c inet: Add a 2nd listener hashtable (port+addr) 2017-12-03 10:18:28 -05:00
ip6_checksum.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ip6_fib.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-19 22:59:33 -05:00
ip6_flowlabel.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
ip6_gre.c net: erspan: use bitfield instead of mask and offset 2018-01-25 21:39:43 -05:00
ip6_icmp.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ip6_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-04-20 10:35:33 -04:00
ip6_offload.c gso: fix payload length when gso_size is zero 2017-10-08 10:12:15 -07:00
ip6_offload.h udp: Add GRO functions to UDP socket 2016-04-07 16:53:29 -04:00
ip6_output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-24 23:44:15 -05:00
ip6_tunnel.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-29 10:15:51 -05:00
ip6_udp_tunnel.c ip6_udp_tunnel: remove unused IPCB related codes 2016-11-02 15:18:36 -04:00
ip6_vti.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-29 10:15:51 -05:00
ip6mr.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
ipcomp6.c net: inet: Support UID-based routing in IP protocols. 2016-11-04 14:45:23 -04:00
ipv6_sockglue.c ipv6: Fix getsockopt() for sockets with default IPV6_AUTOFLOWLABEL 2018-01-23 19:53:24 -05:00
Kconfig ipv6: sr: add helper functions for seg6local 2017-08-25 17:10:24 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mcast_snoop.c
mcast.c ipv6: mcast: remove dead code 2018-01-19 14:17:44 -05:00
mip6.c ktime: Get rid of ktime_equal() 2016-12-25 17:21:23 +01:00
ndisc.c net: ipv6: send unsolicited NA after DAD 2018-01-29 14:18:38 -05:00
netfilter.c netfilter: remove struct nf_afinfo and its helper functions 2018-01-08 18:11:02 +01:00
output_core.c net: accept UFO datagrams from tuntap and packet 2017-11-24 01:37:35 +09:00
ping.c net/ipv6: Convert icmpv6_push_pending_frames to void 2017-10-06 09:52:31 -07:00
proc.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
protocol.c net: Add sysctl to toggle early demux for tcp and udp 2017-03-24 13:17:07 -07:00
raw.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
reassembly.c inet: frags: Convert timers to use timer_setup() 2017-10-18 12:39:55 +01:00
route.c ipv6: change route cache aging logic 2018-01-29 14:22:05 -05:00
seg6_hmac.c ipv6: sr: Use ARRAY_SIZE macro 2017-09-01 18:35:23 -07:00
seg6_iptunnel.c ipv6: sr: add support for encapsulation of L2 frames 2017-08-25 17:10:23 -07:00
seg6_local.c ipv6: use ARRAY_SIZE for array sizing calculation on array seg6_action_table 2018-01-09 11:40:46 -05:00
seg6.c rhashtable: Change rhashtable_walk_start to return void 2017-12-11 09:58:38 -05:00
sit.c net: don't call update_pmtu unconditionally 2018-01-25 16:27:34 -05:00
syncookies.c tcp: Namespace-ify sysctl_tcp_workaround_signed_windows 2017-10-28 19:24:38 +09:00
sysctl_net_ipv6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
tcp_ipv6.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
tcpv6_offload.c gso: validate gso_type in GSO handlers 2018-01-22 16:01:30 -05:00
tunnel6.c ipv6: fix tunnel error handling 2015-11-03 10:52:13 -05:00
udp_impl.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
udp_offload.c gso: validate gso_type in GSO handlers 2018-01-22 16:01:30 -05:00
udp.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
udplite.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
xfrm6_input.c xfrm: Reinject transport-mode packets through tasklet 2017-12-19 08:23:21 +01:00
xfrm6_mode_beet.c networking: make skb_pull & friends return void pointers 2017-06-16 11:48:39 -04:00
xfrm6_mode_ro.c ipv6: xfrm: Handle errors reported by xfrm6_find_1stfragopt() 2017-06-02 13:57:27 -04:00
xfrm6_mode_transport.c ipv6: xfrm: Handle errors reported by xfrm6_find_1stfragopt() 2017-06-02 13:57:27 -04:00
xfrm6_mode_tunnel.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-24 23:44:15 -05:00
xfrm6_output.c xfrm: Add an IPsec hardware offloading API 2017-04-14 10:06:10 +02:00
xfrm6_policy.c net: Create and use new helper xfrm_dst_child(). 2017-11-30 09:54:25 -05:00
xfrm6_protocol.c xfrm: input: constify xfrm_input_afinfo 2017-02-09 10:22:17 +01:00
xfrm6_state.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm6_tunnel.c xfrm6_tunnel: exit_net cleanup check added 2017-11-14 15:46:17 +09:00